This invention relates to the field of munitions in general, and to hand emplaced mines in particular. One munition in particular, designated ADAM, is a gun-launched mine which is meant to lie on the ground's surface when deployed. The mine is then denoted when an enemy comes in close contact with it, by pulling a trip line which lines extend in several directions from the mine. (The lines are gas-propelled to extend out after the mine lands on the ground). There are multiple safeties in the mine to prevent premature and/or unwanted explosions. For example, the mine only commences arming and battery activation while in flight. Mechanical means through a safing and arming (S & A) device sense both spin and set back forces on the mine which puts the explosives in line and also permits a main timer to begin an arming sequence of the mine detonator. The presence of the both these conditions of course, could only be done in the special environmental conditions of gun launch, when there is present both setback of the mine, and also spin of the mine in the launch tube. In addition to these safeties, there are also electrical means which combine to provide an at least 60 second time delay, from time of (battery) power activation, the possibility of initial detonation. A primary timer circuit within the mine, as mentioned earlier, through a firing capacitor generates the 3.0-3.5 volts pulse needed to activate detonation only after a time delay of some 60 seconds. This acts to provide a 60 second delay as above mentioned. The S & A enables the explosive train and also the primary timer circuit generates the approximate 3.0 volt pulse to activate the gas generation means for expelling the various trip lines which provide the detonation drive means. As a further safety to prevent arming before these mines are emplaced into use, the firing circuit electrical output from the said primary timer circuit is shunted with a near dead-short while in the gun. The shunting bar used permits less than 0.5 volts potential to ever exist across those output terminals (which are in parallel to the safing and arming mechanism's detonating input terminals). Since 0.5 volts cannot be enough to ever activate the safing and arming means to detonate the mine, the shunting bar could therefore be considered as a closed switch (until cut open at launch) whereupon it becomes an open circuit. In addition, a battery aboard the mine is also not engaged to power the mine until launch whereupon a mechanical means causes the battery to be engaged to activate the mine's circuitry when a ball is pushed in upon the mine's exiting from the projectile. Also, the shunt bar (which is physically an approximately 1/2" strip of sheet brass), is physically cut or ripped apart, as the mine exits from the projectile through contact with a tool for this purpose which engages it while the mine passes through. The timing circuit, activated by the battery, now stands ready to generate its 3.0-3.5 volt pulse at the end of 60 seconds time, and there is no longer a shunt bar to dead-short this pulse when it does get generated, for it has been cut. Of course, upon beginning flight and coming to rest on the ground, the primary timer circuit expels a plurality of tripwires which can be tripped when contacted. The mine is now fully activated and ready to be tripped by an approaching enemy. One can see the many safety features in this mine which only enable it to be armed by being properly launched from the gun, and not through an accident. After landing, the mine awaits detonation when stepped on or about, and tripped by the pursuer. It is known that after another pre-selected longer length of time, the mines then also automatically detonated. This is done so that the field will again be clear to friendly soldiers after a certain length of time, without mine clearing.
It is now proposed that the ADAM mine be simply dropped by hand, rather than launched out of a gun. The soldiers could simply drop the mines, to engage an enemy which is pursuit of them. The mines would become armed shortly thereafter and therefore later explode when stepped on by the pursuing enemy or when the enemy comes into close contact therewith during pursuit, but never before a 60 seconds' time duration, on account of the timer circuit earlier described. This time delay of course is comfortable and a necessary safety for the friendly soldiers, since otherwise the mine might go off unexpectedly even upon being hand-emplaced by the friendly soldier. The 60 seconds is not, on the other hand, difficult to live with. It is compatible with typical pursuit times, and is in effect better than a hand grenade which actually has too short a detonation time for such pursuit situations. The now to be hand-emplaced variation of the ADAM mine has of course several mechanical modifications over the original gun-launched type mine design. Instead of the battery being activated upon launch from a gun by automatic mechanical pushing in of a ball, now the ball is plunged in by the soldier forcibly closing a heavy bar. There is no more sensing for spin or set-back forces, since this is no longer in a gun-launched environment, and significantly, there is still a shunting bar for removal in this design (done by the same action as activating the battery). One can see now, that except for the select battery activation and the 60 second time delay caused by the primary timer-circuit, there are now no more safety features in the mine. If the primary timing circuit malfunctions with a premature pulse, there is nothing to save the friendly soldier from an immediate detonation. The cutting of the shorting bar upon launch approach is used, say by being cut when the soldier draws the heavy bar to activate the battery. The cutting actually adds nothing in the way of safety, since the soldier is directly proximate the mine (unlike in the gun-launched situation where when the bar is cut there is a safe separation distance from the gun/soldier), and there is nothing but the timing circuit to prevent the mine from going off. As explained before, an at least double safety to the timing circuit is necessary, and now sought to be devised, therefore.
It is of course far less important if the mine fails to detonate, as in a dud, than if it accidentally explodes when a soldier is holding same. In fact it is a design goal to have less than one device per 100,000 as unfortunately defective in terms of premature explosion. This premature explosion caused by the failure of both the primary timer-circuit, and also of a back-up safety mechanism as to be proposed by this invention will become much more remote because of the joint probability of failure of two mechanisms at the same time.